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Finding the Fourth Proportional to 781.66, 1,078.74 and 450.17

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Solution

The fourth proportional to 781.66, 1,078.74 and 450.17 is: 621.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    781.66 : 1,078.74 = 450.17 : x
  2. Step 2: Convert to fraction form
    781.66/1,078.74 = 450.17/x
  3. Step 3: Cross multiply
    781.66x = 1,078.74 × 450.17
  4. Step 4: Simplify right side
    781.66x = 485,616.39
  5. Step 5: Solve for x
    x = 485,616.39/781.66
  6. Step 6: Final answer
    x = 621.27

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.